Blasting-cartridge.



No. 889,639. 1 I PATBNTED JUNE 2, 1908. P. SELBAGH.

BLASTING CARTRIDGE.

nrmonmn FILED MAR.13, 1907.

THE "alum; PE'rxRs 00., wAsumornu. n. c.

In re)? Z01 rinrnn snares PATNT FFIQEQ B LASTING -CARTRID GE Specification of Letters Patent.

Patented June 2, 1908.

Application filed March 13, 1907. Serial No. 362,214,.

To all whom it may concern:

Be it known that I, PETER SELBACH, a citizen of the Empire of Germany, residing at Cologne-on-the-Rhine, in the Empire of Germany, have invented a new and useful Blasting-Cartridge, of which the following is a specification.

My invention consists of improvements in blasting cartridges, whereby the latter are rendered specially suitable for blasting operations under water.

I employ a known metallic case and provide it with a screw-plug, which is adapted to be screwed into the case for more or less compressing the explosive, in which a detonator is placed, so as to remove all the air spaces and thereby to insure a better detonation. This screw-plug is provided with a preferably central bore and a stuffing-box for tightening the conducting wires or their equivalents which are connected with the detonator. Thereby the filling, emptying and recharging of the metallic case is rendered easy, while every danger of explosionis avoided. In case the conducting wires or their equivalents are torn off by chance, it would be impossible to make any use of the blasting cartridge, which must be left in its borehole. The blasting cartridge may also fail to explode for the reason, that water has penetrated into the explosive, or there may be other circumstances which prevent an explosion of the cartridge. In such cases it would for obvious reasons not be advisable to withdraw the cartridge from its bore-hole by means of its conducting wires or their equivalents, so that the cartridge must equally get lost. To remove this defect I connect the screw-plug or its stufling-box with suitable drawing means, such as chains, cords or the like, for withdrawing the blasting cartridge from its bore-hole without any danger. Then the cartridge can be examined and if necessary its charge may be re placed by a fresh one. Hitherto it was further impossible to ascertain with perfect safety whether all the several blasting cartridges used for a blasting operation did actu ally explode or which of them did fail. I therefore provide floats and connect them with the upper ends of the chains, cords or the like. Then these floats will show, whether an explosion of the cartridge has taken place or not.

I will now proceed to describe my invention with reference to the accompanying drawing, which is an elevation of a blasting cartridge, a part being shown in section.

a is a metallic cartridge case which at its upper end is provided with an internal screwthread. Into this screw-thread a screw-plug 0 can be screwed in any known and approved manner, for example by means of a screwkey placed over its hexagonal head 6. The plug 0 is provided with a central bore n and an internally screw-threaded hole 1), so that it forms a stufling box. The screw-threaded gland (Z of the latter has a suitable crosshead f with several (here two) eyes 9 and h. Drawing means, for example chains '1; 'i as shown or the like, are attached to the eyes 9 and h in the crosshead f of the gland d and are made of a convenient length. Floats v o of any known construction, for example disks of cork as shown, are attached to the other ends of the chains it or the like. The latter are made so long as to permit the floats o o to still float on the level of the water after the cartridge has been introduced into the respective bore-hole under water.

76 denotes a detonator of any known and approved construction, the two wires Z and m of which pass upwards through the bores n and 0 of the screw-plug c and the gland d respectively.

It will be understood, that when filling the case a with explosive b and introducing the detonator 76 it is easy to remove all the air spaces within the case a u to the bottom face of the screw-plug c, which latter is properly screwed home by means of a key engaging its hexagonal head 6. The space round the two wires Z and m in the two bores n and 0 and in the stufling box 79 is packed with some suitable material, such as for instance fat or lamp-wick impregnated with fat or the like, and the gland d is screwed home to render the joint water-tight. The blasting cartridge so formed is introduced into the respective bore-hole under water in any known manner, care being taken, that the floats o 1; remain visible on the upper surface of the Water and mark the place, where the cartridge lies. If everything is in order, the cartridge can be exploded in the usual manner. When the explosion actually occurs, the chains i i will be broken or torn and the floats 'v '0 will be thrown off or disappear and thus indicate the explosion. If, on the contrary, from some reason no explosion takes place, the floats o Q) will remain on their places and thus show, that something is wrong, be it that the wires Z and m have broken or the like. In this case it ispossible to withdraw the cartridge from the bore-hole in the rock under water by means of the chains it or the like and to examine the cartridge without incurring any risk of premature explosion. The screw-plug 0 may be screwed OE and the explosive b may be taken out of the case a and, if necessary, be replaced by fresh explosive. Itis also possile to further compress the explosive b by means of the screw-plug 0 without any danger to the workman, so as to insure a better detonation of the explosive.

The blasting cartridge described may be varied in many respects without departing from the spirit of my invention.

I claim:

1. In a blasting cartridge, the combination with a substantially cylindrical metallic case open and internally screw-threaded at the wide end, of explosive and a detonator in said metallic case, conducting wires connected with said detonator, and a screw-plug fitting in the screw-threaded open end. of said metallic case and adapted to compress said explosive for avoiding air-spaces, it being provided with a bore filled with packing material for said conducting Wires.

2. In a blasting cartridge for blasting operations under water, the combination with a substantially cylindrical metallic case open and internally screw-threaded at the Wide end, of explosive and a detonator in said metallic case, conducting wires connected with said detonator, a screw-plug fitting in the screw-threaded open end of said metallic case and adapted to compress said explosive for avoiding air-spaces, it being provided with a bore filled with packing material for said conducting wires, and drawing means attached to said screw-plug for withdrawing the cartridge from its bore-hole if required.

3. In a blasting cartridge for blasting operations under water, the combination with a substantially cylindrical metallic case open and internally screw-threaded at the Wide end, of explosive and a detonator in said metallic case, conducting wires connected with said detonator, a screw-plug fitting in the screw-threaded open end of said metallic case and adapted to compress said explosive for avoiding air-spaces, it bein provided with a bore and a stuffing-box filled with packing material for said conducting wires, and chains attached to said screw-plug for withdrawing the cartridge from its bore-hole if required.

4. In a blasting cartridge for blasting operations under water, the combination with a substantially cylindrical metallic case open and internally screw-threaded at the wide end, of explosive and a detonator in said metallic case, conducting wires connected with said detonator, a screw-plug fitting in the screw-threaded open end of said metallic case and adpated to compress said explosive for avoiding air-spaces, it being provided with a bore and a stuffing-box filled with acking material for said conducting wires, crawing means attached to said screw-plug for with drawing the cartridge from its bore-hole if required, and floats at the other ends of said drawing means for showing whether an explosion has taken place or not.

5. In a blasting cartridge for blasting operations under water, the combination with a substantially cylindrical metallic case open and internally screw-threaded at the wide end, of explosive and a detonator in said metallic case, conducting wires connected with I said detonator, a screw-plug fitting in the screw-threaded open end of said metallic case and adapted to compress said explosive for avoiding air-spaces, it bein provided with a bore and a stufiing-box filled with packing material for said conducting wires, chains attached to said screwlug for withdrawing the cartridge from its ore-hole if required, and floats at the other ends of said chains for showing whether an explosion has taken place or not.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

PETER 'SELBAOH.

Witnesses:

BESSIE F. DUNLAP, LoUIs VANDORN. 

